Most pulsed power machines require the use of resistors that are subject to high voltage and high power dissipation. Aqueous-electrolyte resistors have traditionally been used in pulsed power systems for fast voltage-divider probes, charging/trigger resistors in Marx banks, dummy loads, absorbers of reflected pulses, and capacitor bank dumps. These water-based resistors are simple, robust, have low-inductance, are capable of operation at high voltage and high current, and are capable of dissipating large pulse energies while preserving their operating capacity. Further, the resistivity can be easily changed simply by adjusting the electrolyte concentration. See R. E. Beverly and R. N. Campbell, Rev. Sci. Instrum. 66, 5825 (1995); and A. I. Gerasimov, Instrum. Exper. Tech. 49, 5 (2006). However, water-based resistors have some problems. If the water resistor leaks, the water will degrade the dielectric strength of the surrounding oil, which is often used as an insulator in pulsed power machines. Also, the charge flow through the resistor is limited by the resistivity of the water solution. As the resistivity of the solution increases, the total charge through the resistor must be reduced to avoid electrolysis which can generate gas in the resistor. See R. V. Whitely and J. M. Wilson, IEEE Power Electron. Specialists Conf., 654 (1983). For these reasons, solid-state resistors have been pursued for many years as a possible replacement. However, most solid-state resistor designs have a number of other problems, such as inflexibility, low power tolerance, and low voltage hold off.
Therefore, a need remains for a solid-state resistor that can be used in pulsed power machines.